Once you've sent all letters in a batch, you can archive or delete it. Archived batches remain on your system; deleted batches do not.
To delete a batch:
Click the Mail tab and click the Batches submenu link to go to the Quick Search page for batches.
Search for the batch you want to delete by performing a quick or advanced search. Found batches appear on the Search Results page.
Select the check box next to the batch or batches you want to delete.
Select the Delete action.
Click OK to confirm the deletion.
Note: If you delete all mail in a batch or all People records that have mail in a batch, the batch is automatically deleted.